The thirst for enhanced sensitivity brought to extremely sophisticated systems. The current paradigm for optical instrumentation is to design larger and larger telescopes properly armed with Adaptive Optics (AO) modules. Such effort caused an analogous complexity of the camera/spectrograph response. The ground-based PSF, which was seeing dependent, now is time-evolving and spatially varying on minutes and arcsecond scales, respectively. The stochastic behaviour of both the optical turbulence and the telescope vibrations corresponds to an unreliable PSF definition. A long-time average may reduce the divergence with respect to predictions, reducing the problem to an accurate knowledge of the initial conditions. Accurate photometry and morphological studies require accurate PSF knowledge. The PSF information is mandatory, but the availability of point sources is not obvious, since the field of view imaged by AO instruments is typically small (tens of arcsec).
We focus on the blind PSF-reconstruction[1]}, [2]} (PSF-R). It is “blind” because applies to the cases when the PSF reference is not available: when the only viable way to build a PSF is to use complementary information made available by the observatory (seeing, wind speed) or by the AO instrument (otherwise, i.e., see Massari+ (2020)[3]}). These “telemetry” data offer the opportunity to reduce the PSF object to parameters describing turbulence statistics, AO loop, noise, vibrations, and the optical train. We describe a possible method, we are developing using the SOUL[4]}, [5]}@LBT[6]} AO module, and the LUCI[7]} imager as the reference application.
SOUL recently upgraded the FLAO[8]} systems at the LBT replacing the wavefront sensor camera with an OCAM2k[9]}.
The FLAO and SOUL are SCAO adaptive optics modules.
Thanks to the low readout noise camera, finer pupil resolution and increased readout frequency SOUL improves several merit figures: sky coverage, magnitude limits, and Strehl Ratio values (optical quality)
SOUL, as the First Light Adaptive Optics (FLAO)[8]} did, feeds the NIR camera LUCI.
